Parametric Study of Welded Gusset Plates Performance in Concentric Braced Steel Frames under Cyclic Loading

The behaviour of gusset plates in concentric braced steel frames has been studied. Parameters studied are the thickness and shape of the gusset plate, use of linear and elliptical clearance, non-existence of clearance, edge, longitudinal and internal stiffeners, and use of a single- or double-profile bracing. Analysis has been performed by the three-dimensional non-linear finite element method using the ABAQUS code. Cyclic loading has been used. By eliminating the clearance, the plastic strains in weld between the gusset plate and bracing and plastic strains in the gusset plate are increased. In the weld between the gusset plate and bracing, the existence of any type of stiffeners has increased plastic strains compared to unstiffened gusset plates. In most cases, edge and longitudinal stiffeners have decreased plastic strains of the gusset plate and internal stiffeners have increased them The maximum energy dissipation has belonged to edge stiffeners with an increase of 15.4% compared to unstiffened gusset plates. By decreasing the thickness from 24 mm to 18.8 mm the maximum stress has been decreased by 3.5%. For similar gusset plates, use of single-profile bracing instead of double-profile bracing has not changed the value of maximum lateral load for compressive bracing. In this case, most of variation has belonged to the plastic strains of the weld between the gusset plate and bracing with an increase of 30% in a rectangular plate with a linear clearance and a reduction of 65% in a rectangular plate without clearance compared to a double-profile bracing.